Which of the silk road cities in this chart offered silk in exchange for other goods?

Cities grew up along the Silk Roads as essential hubs of trade and exchange, where merchants and travellers came to rest themselves and their animals, and to start the process of trading their goods. From Xi’an in China to Bukhara in Uzbekistan, from Jeddah in Saudi Arabic to Venice in Italy, cities supplied the ports and markets that punctuated the trade routes and gave them momentum. After travelling for weeks on end across inhospitable deserts and dangerous oceans, they provided an opportunity for merchants to rest, to sell and buy, and moreover, to meet with other travellers, exchanging not only material goods but also skills, customs, languages and ideas. In this way, over time, many Silk Road cities attracted scholars, teachers, theologians and philosophers, and thus became great centres for intellectual and cultural exchange, and  building blocks in the development of civilizations throughout history

Explanation:

i am pretty sure it is d.